Project Summary/Abstract The American Academy of Pediatrics (AAP) recommends a staged approach to the management of pediatric overweight and obesity, starting with Stage 1, Prevention Plus, which encourages families to improve lifestyle choices related to eating and activity in order to improve BMI status. Most pediatric practices have difficulty implementing these guidelines, however, due to limited time and access to weight loss experts to whom they can refer their patients and families, and burden to families in accessing in-person weight loss services. In response, our team developed the FITLINE pediatric practice-based referral program which provides practices an easily accessible resource to help families make AAP-recommended lifestyle changes. The program includes two components: (1) a pediatric practice-based component based on the Let's Go 5-2-1-0 intervention involving systems to assess and document BMI, a healthy habits screener and brief provider- delivered intervention, referral to the FITLINE counseling program, and feedback from the FITLINE nutritionist; and (2) a parent support component consisting of eight weekly FITLINE telephone counseling calls by centrally located nutritionists to provide parents coaching tailored to their family's unique needs and culture to help them set goals and make targeted lifestyle changes recommended by the AAP for Stage 1, Prevention Plus, accompanied by a parent booklet. The proposed five-year cluster randomized controlled pediatric practice-based trial will compare the effectiveness of two practice-based interventions on improving diet and physical activity and reducing BMI among overweight and obese 8-12 year olds seen in pediatric practice: (1) PP-FITLINE, consisting of the pediatric practice-based component plus FITLINE counseling and booklet, or (2) PP-Materials, consisting of the same practice-based component, but only the parent materials mailed over 8 weeks, with no referral to FITLINE counseling. Sixteen pediatric primary care practices will be randomized to either the PP-FITLINE (N=8) or the PP-Mailings (N=8) condition. Five hundred and twelve parents and their children ages 8-12 with a body mass index (BMI) of > 85th percentile (overweight or obese) will be recruited from the practices to achieve N=400 at 12 month follow-up. Assessments will be completed at baseline and 6- and 12-months post-baseline. The specific aims of this study are to determine the effectiveness of the PP-FITLINE program in reducing BMI in overweight and obese children and improving the child's diet and physical activity behaviors; explore possible mechanisms of the effect of the PP-FITLINE program on BMI, diet and physical activity; and estimate the cost-effectiveness of the PP-FITLINE compared with the PP-Mailing program. If found to be effective and cost-effective, the PP-FITLINE program will provide an innovative model which can be scaled up for widespread implementation of Stage 1, Prevention Plus of the AAP expert committee recommendations through pediatric practices nationwide, contributing significantly to the development of new standards for weight management care in pediatric practice.